Door control mechanism



Sept. 1, 1953 E. 1.. ALLEN DOOR CONTROL MECHANISM 9 Sheet s-Sheet 1 Filed 001.- 20, 1949 l l l I I l I l I l l l l I l l I FlGi JNVENTOR. L. ALLEN AT TORNEYS E Sept. 1, 1953 E. L. ALLEN 2,650,346

' DOOR CONTROLMECHANISM Filed Oct. 20, 1949 9 Sheets-Sheet 2' I I INVENTOR.

EDWIN L. ALLEN ATTORNEYS p 1, 1953 E. L. ALLEN 2,650,846

DOOR CONTROL MECHANISM Filed Oct. 20, 1949 9 Sheets-Sheet 3 IN V EN TOR.

EDWIN L. ALLEN 5G4 I I.

Sept. 1, 1953 E. ALLEN DOOR CONTROL MECHANISM Filed Oct. 20, 1949' I INVENTOR. EDWIN y L. ALLEN i M *M 9 Sheets-Sheet 4 l HTTOPNEYS Sept. 1, 1953 E. L. ALLEN 2,650,346

DOOR CONTROL MECHANISM Filed Oct. 20, 1949 9 Sheets-Sheet 5 INVENTOR. EDWIN L. ALLEN AT TOPNEYIS p 1953 E. ALLEN 2,650,846

DOOR CONTROL MECHANISM Filed Oct. 20, 19.49 9 Sheets-Sheet 6 106 I 4 JNVEN TOR. EDWIN L. ALLEN A TTO PNEYST Sept. 1, 1953 E. 1.. ALLEN DOOR CONTROL MECHANISM 9 Sheets-Sheet '7 INVEN 10R.

HTTOEAIEYS' ljlowm L. ALLEN Filed Oct. 20 1949 Sept. 1, 1953 E. L. ALLEN 2,650,846

DOOR CONTROL MECHANISM Filed Oct. 20, 1949 9 Sheets-Sheet 8 A TTOPNEVS d0 4 OJ 2 r M m mwwwm up flu n 4 M i E 3 3 a r W 2 Wm H Al 4 2 L & aw F L G vf n T 15 (M0, aw mw W x I 1..\ 5 m I. m m flnmnnn m w 0 Q I E? FIG. 25

P 1, 1953 E. L. ALLEN 2,650,846

DOOR CONTROL MECHANISM Filed Oct. 20, 1949 9 Sheets-Sheet 9 INVENTOR.

EUWBN L. ALLEN BY ATTOPNEY5Y l atented Sept. 1 1953 U N'ITED STATES PAT ENT OFF ICEv noon CONTROL MECHANISM Edwin L. Allen, Cleveland Heights, 'Ohio, as-

signor, by mesne assignments, to Rudolph I.

S'chonitzer, Cleveland, Ohio ApplicationOctober 20, 1949, Serial No. 122,436

11 "Claims.

frame structures whereby the door may be latched and held in closed position or unlatched and released to permit it to be moved into open position. In general, a push button, a plunger, a handle or the like is employed through which may be exerted part or all of the force expended in moving the door from door-latched to doorunlatched position; indeed, the invention in one of its aspects contemplates the provision of a latch structure by which actuation of the latch mechanism incident to opening the door may be initiated by operation of a push button or the like but further force must be applied tocomplete the operation of unlatching and opening the door.

Oneof the principal objects of the invention is the provision of a compact, rugged and inexpen- SiVe latch mechanism particularly adapted for use with automobile doors. Other objects include the provision of an improved control mechanism by which actuation of what is hereinafter referred to as the latch member may be impeded or permitted; the provision of improved spring means which, in moving from one to the other of two terminal positions, during part of its travel exerts a force urging the parts into door-latched relation and during another part of its travel urges them into door-unlatched relation; and, the provision of effective means for restraining or permitting movement of the latch member together with means, operable from either the interior or the exterior of the vehicle, for movi'ng the latch-restraining member into latchlocked or latch-unlocked position, as may be desired.

Other objects and advantages of the invention will appear from the written description which follows, taken with the accompanying drawings in which:

Figure l is a side elevation of a vehicle door in which my latch mechanism is incorporated, but on a reduced scale as compared with certain of the other figures;

Figure 2 is an end elevation of the same door,

looking at the free edge thereof and likewise on 7-1 a reduced scale as compared with certain of the other figures;

Figure 3 is an enlarged vertical cross-sectional view, with parts broken away, taken substantially on line 3-3 of Figure 1;

Figure 4 is a vertical cross-sectional View taken substantially along line 44 of Figures 2, -3 and Figure 5 is a horizontal cross-sectional View taken substantially along line 5-'-5 of Figures 2, 3 and 4;

Figure 6 is a detached view of the mechanism of Figure 3, the door structure being omitted however and the latch member being shown in its intermediate or secondary latched position;

Figure '7 is a fragmentary view showing the latch plate and control slide member and taken substantially on line l'1 of Figure '6;

Figure 8 is a fragmentary view of the control slide member as seen from line 88 of Figure 3;

Figure 9 is a cross-sectional view of the control slide member taken substantially on line 99 of Figure 8;

Figure 10 is a view generally similar to Figure 6 but showing the latch member in door-unlatched position and taken substantially on line lit-l U of Figure 11;

Figure 11 is a vertical cross-sectional view taken substantially on line 'I E-Il of Figure '10;

Figure 12 is an enlarged vertical cross-sectional view of the remote control push button, et-c., taken substantially on line 12-42 of Figure 1;

Figure 13 is an enlarged vertical cross-sectional view of the remote control shaft and bracket taken substantially on line |3l3 of Figure 1;

Figures l t and 15 are views generally similar to Figure 6 but illustrating -a modification employing a compression spring, Figure 14 showing the latch member in latched position and Figure 15 showing it-in unlatched position;

Figure 16 is a detail, largely in section, of the spring assembly of Figures 14 and 15 as seen from line I 6l-6 of Figure 14;

Figures 17 and 18 are details showing the manner of mounting the cover plate on the base plate and guiding the control member, as seen from lines 11-41 and 1 8-1 8, respectively, of Figure 14;

Figures 19 and 20 are views corresponding generally to Figures 14 and 15 respectively but illustrating a further modification employing a tension spring rather than a compression spring;

Figure -21 is a detail, largely in section, of the Spring assembly of Figures 19 and 20 as seen from line 2 l-2l of Figure 19;

Figure 22 is a detail, largely in section, of the interior mechanism as seen from line 2222 of Figure 19;

Figure 23 is a view corresponding generally to Figure 3 but showing still another modification;

Figure 24 is a vertical cross-sectional view taken substantially on line 24-24 of Figure 23;

Figure 25 is a horizontal cross-sectional view taken substantially on line 25-25 of Figure 23; and

Figures 26 and 2'7 are views of the mechanism of Figure 23 and generally similar thereto but respectively showing the parts in secondary latched and door-unlatched positions.

Referring first to Figures lto 5, inclusive, door D includes, along with the various other conventional elements which go to make up the door of a vehicle, such parts as outer panel I, inner panel 2, and edge wall 3. The latterconceals the interior construction of lock pillar 4. On edge wall 3 and within lock pillar 4 is mounted a door latch housing H. Positioned inwardly of housing H for movement between the usual raised and lowered positions in door D is a window glass shown inraised position in solid lines and in lowered position in phantom lines 5. Door D is mounted on and in a manner to permit it to close against body pillar T of the vehicle.

Housing H, which is aifixed to edge wall 3 by means of screws 6, embodies a base plate 7 which is mounted immediately within edge wall 3. As shown in Figures 4 and 5, base plate has along one side thereof an inwardly directed edge flange la, such flange extending the full length of base plate 1 along the side thereof in juxtaposition to inner panel 2. Cooperating with base plate I but spaced from flange 1a thereof is a cover plate 8, one side of which abuts and is closed by an inwardly directed edge wall 9 which is integral with base plate 1 but which is coextensive with cover 8 on the side thereof in proximity to outer panel I. Cover plate 8 is provided with two integrally formed end walls Ila and Nb which respectively define the upper and lower limits of the cover plate and on which are formed two oppositely directed portions 8a and 817 that, as illustrated in Figure 4, project through and are bent over into firm contact with base plate 1.

These various elements, which collectively make up housing H, form part of the frame structure supporting a latch mechanism hereinafter to be described incorporating an externally positioned latch member L characterized by legs L and L", of which the former, which adjoins inner panel 2, is somewhat shorter than the latter. Latch member L cooperates with a stationary keeper pin P mounted as shown in Figures 4 and 5 on body pillar T. Associated with pin P ar the usual elements for adjusting and supporting it and for preventing rattling of latch member L. These elements are not described in detail as they are not a part of the present invention.

Latch member L is carried upon a squared-off shaft l2 supported for rotation in base plate 1 as best shown in Figure 5. On the opposite side of base plate 7, shaft l2 carries a latch plat or element 13 which, like latch member L, is rigidly fixed to shaft [2. Thus shaft [2, latch plate 53 and latch member L rotate as a unit, such rotation being limited in extent and characterized at its extremes by the door-latch and the door-unlatched positions respectively shown in Figures 3 and 10. Between them is an intermediate or secondary latched position in which the parts as sume the relationship indicated in Figure 6.

As shown in Figures 3, 6, and 10, latch plate I3 has a generally rounded lower portion and an irregularly shaped upper portion. Proceeding clockwise thereof with the parts of the latch in the relationship illustrated in Figure 3, the upper portion of latch plate I3 is characterized by a rectangular notch 15 at the left-hand side of the upper portion, by a V-notch l6 toward the right center thereof, and by a downwardly extending lateral notch located diametrically opposite the rectangular notch. Between the notch portions, proceeding clockwise, are an abutment portion l4 and a latch stop portion 2|. The abutment portion I4 is formed between rectangular notch 15 and V-notch l6 and is characterized by a flat face I! which, in the door-latched position illustrated in Figure 3, engages flange Ia of base plate I; on the opposite side of abutment portion !4 is a like flat fac I8 which, in the door-unlatched position illustrated in Figure 10, abuts edge wall 9 on base plat 1. Toward the top of abutment portion 1 4 is an elongated spring-receiving slot [9.

Latch stop portion 2|, which is defined on one side by V-notch l6 and on the other side by the lateral notch opposite rectangular notch I 5, is characterized by an arcuate contour and by an edge flange 22, likewise arcuate in shape, which extends inwardly, i. e., away from base plate I and toward cover plate 8. Arcuate flange 22 constitutes a holding portion which cooperates with a control slide member to be described. Similarly, abutment portion l4 cooperates with a latch-restraining member to b described, this more particularly by virtue of the part thereof which immediately overlies rectangular notch l5, which part may be described as a restraining-member engaging element comprising part of a locking abutment portion which itself form part of latch plate l3.

Cooperating with spring-receiving slot I9 in abutment portion I4 is a snap-over spring 23 which, in the embodiment of the invention illustrated in Figures 1 to 13, takes the form of a coil spring the ends of which tend to spread apart. Lower end 24 of snap-over spring 23 is received in and projects through slot I9 as shown in Figures 4 and 11. Upper end 25 of snap-over spring 23 is anchored in cover plate 8, projecting oppositely to lower end 24 through a suitable opening 26 in cover plate 8. Snap-over spring 23 has two terminal positions, shown in Figures 3 and 10 respectively, and between them goes through an infinite number of intermediate positions one of which is represented by the showing in Figure 6. Slot l9 extends at an acute angle to radii drawn from the center of shaft l2 to the ends of slot l9 and permits end 24 of spring 23 to move downwardly during movement of the latch member L from unlatched position to latched position thus avoiding excessive loading of the spring during such movement.

When latch plate I3 is in the position shown in Figure 3, that is to say in door-latched position, snap-over spring 23, acting on abutting portion l4 at the top part of spring-receiving slot 19, tends to urge latch plate l3 counterclockwise, thus maintaining abutting face I! in contact with flange Ia of base plate I. In door-unlatched position, illustrated in Figure 10, snap-over spring '23 acts on abutting portion 14 at the bottom part of spring-receiving slot l9, urging latch plate [3 clockwise so that abutting face I8 is in contact with edge wall 9 on base plate I, as shown in Figure Betw'eeii these two positions; for exam ia in-the secondary latched position of latch member L, snap-over spring 23- assumes an in termediate position such as that illustrated in Figure 6. In the course of its movement between its two terminal positions, 1, etween dotted line position '23" Figure 10 and the solid line positionimmediately below it, Snap-0W1 spring 23 urges latch plate 23 and latch member L toward -dooi"-latched position during the initial part of its travel and toward door unlatohed position during the final part of its travel.

As is indicated in Figures 3-, 5, 6 and 10, my invention contemplates the use or a selectively positioned control member 21 (hereinafter sometimes called the control slide member), which, in its normal position, precludes the possibility of substantial rotation of latch plate out of the latched position of Figure 3. As seen in side elevation in Figures '3, 6 and ill, control slide member 21 is generally la-shaped having an upwardly extending branch '28 and a laterally extending branch 34. Upwardly extending branch 28 has rig-idly affixed thereto a rod 29 of which the outermost portion '3! serves as a manually operable push button or plunger accessible from the outside of the vehicle. Plunger 3-! is surrounded by a guide 32 held in position in outer panel I which guide is formed integrally with a stationary handle 3-3 for use in opening and closing door D from the outside of the vehicle. When plunger 3| is moved inwardly from the position of Figure 3, upwardly extending branch 28 of control slide member 2'! assumes the retracted dotted-line position 28' indicated in Figure 5.

Ether par-ts of control slide member 2'! move linearly to assume correspondingly retracted positio'n's.

As best shown in Figures 3, 4 and 11, the laterally extending branch 34 of control slide member 2'! is provided at its end with an in-turned flange. The latter is itself provided with a centrally positioned inwardly projecting extension 35d which is somewhat narrower than flange 35. Extension 35a projects through and moves in a slot El in cover plate 8 formed between two integrally formed in-turned guide flanges 36a and 36b which appear in Figures 3, 4 and 11 and also in Figures '5, 6 and 10. Edge wall- 9 of housing H is lanced or otherwise formed to provide a slot between lips 38a and 38?) which serve as guides for lateral. branch 34 of control slide member 2! where the latter enters housing H. Thus control slide member 2"! is supported on one side by .guide flanges Eta and tfib and on the other side by lips 38a and 38b. The horizontal dimension of slot 3'? helps determine the extent of permissible lateral movement of control slide member :2? by limiting movement to the right as seen in Figures 3, 6 and 10, while lips 38a and 38b serve to limit movement of control slide member 21 in the opposite direction by acting'as abutments for up wardlyextending branch 28.

Between the ends of branch 34 of control slide member 2'1 is an off-set portion, generally a'rcuate in shape, which is itself divided into an upper arcuate portion 39a and a lowerarcuateportion 3% which are off-set relative to "each other. Between upper arcuate portion 39a and lower arcuate portion 39b is a step 40, shown in Figures 3 and-6 to It, inclusive, which constitutes asecondary blocking portion the purpose of which will appear hereinafter. The upper end of offset portion 39a constitutes the blocking portion as willalso appear later.

At the inboard end or horizontally extending branch 8-! of control slide member 2'! is aleaf spring 12 urging flange 35, and therefore control slide member 21, into the relationship to the other parts which it assumes in the door-latched position illustrated in Figure 3. Upper end 'ls'of leaf spring #2 bears against flange while lower end 44 of leaf spring '43 projects through-and is bent into contact with lower end wall H 1) of cover plate 8. A portion of leaf spring [2 be tween upper end 48 and lower end M engages flange in on cover plate 1. When plunger 31 is operated from the exterior of the vehicle, leaf spring 42 resists, and must be overcome to permit, movement of control slide member 21 in unlatch ing -direc'tion.

As shown-in Figures 1, 5 and '11 to 13, provision is further made for interior or remote control actuation of control slide member 21, including an operating arm #5 which makes contact with the sideof extension Eta opposite from spring 32. Operating arm "45, as indicated in Figures 3, '8 and 19, is firmly attached to a long-itu'd'inally'extending remote oontrol shaft 4%, as at 45a. Sh-art at is mounted between the door panels I and 2 inside door D for limited rotary movement. The inner end of shaft W6 is journal'ed at It (Figure 11) in cover plate 8 of housing I-I. its opposite end shaft 46 is characterized by a dependportion 5 2 that leads to a remote control station accessible from inside the vehicle.-

acent the depending portion of shaft 48 is a mounting bracket 28, shown in Figures 1 and 13, which is mounted on inner panel 2 of door 2). To hold shaft 45 in the desired relation to mounting bracket 48 a strap l-ike retaining member 49 is employed, the ends 49a and 49b of which extend through and are bent to secure them to the body portion of mounting bracket 48. Adjoining mounting bracket '48 is a coil spring 5 biasing shaft #6 in :an angular :direction such as to-eliect engagement between operating arm 45 and extension 35a of iflange 35 on control :slid-e member 21. One :end oi "coil spring 5! abuts the 'ilepending portion '52 of shaft k-5., to which is afiixe'd a push button assembly Z53 surrounded by a shield 54' forming part of the remote control station ('seelFigure 12)..

Einprder to enable the door-control-me'ohanism to be looked a generally T-zshaped restraining member 55 is provided which is shown to best advantage-in Figures land 11 but which appears also in Figures 3, 6 and 10. Restraining member 55 vis'pivoted on a pin .56 for movement between latch-locked position (Figure 3') and a latchunlocked position (Figure 11). As seen :in Fig ures 3, 6 and 10, restraining member 55 includes anuppe'r ofi set portion 5T'Whi0h is spaced somewhat "from (flange 1a of housing H in vorder to permit positioning of a snap-over spring '58 in the space so provided. As shown in Figures :4 and 11, a hole 59 is formed in upper off-setportion'51 forreceiving'the free ienddl of snap-over spring 58, while the fixed end 62 of snap-over spring "58 is anchored in .flange 1a, passing through a hole'fifltherein.

Upper off-"set portion '51 of restraining member 55 includes 'a polygonal abutment member 53 which, when restraining member -55 is in its latch-unlocked position, abuts base plate 1 as indicatedin Figure 11.

Restraining member '55 is characterized also by a lower ofiset portion 64 spaced 'from flange 1a of'base plate 1. Lower ofi-set portion 64 includes a latch plate engaging element :65 :illus trated in Figure 4 in the position which it assumes when member 55 is in latch-locked position. When in this locked position element 65 projects into the notch in latch plate l3. Snap-over spring 58 maintains the parts in this position, thereby effectively blocking rotary movement of latch plate 13 until such time as restraining member is moved into latch-unlocked position.

The latch-unlocked position of restraining member 55 is shown in solid lines in Figure 11; in such position, snap-over spring 58 urges restraining member 55 and latch plate engaging portion thereof in unlatching direction and out of blocking engagement with latch plate l3.

For manually moving restraining member 55 between its two positions, an actuating rod 66 is provided. Actuating rod 66 has a grasping portion 61 at the upper end thereof by which it may be moved from the solid line position shown in Figure 4 to the dotted line position indicated therein by 66; at the same time, grasping portion 6! assumes the dotted line position indicated by 61'. When grasping portion 51 and actuating rod 66 are in the elevated position, respectively indicated by 61 and 66, restraining member 55 occupies the unlocked position shown in solid lines in Figure 11. When grasping portion 61 and actuating rod 66 are in their depressed position, restraining member 55 isof course in the solid line locked position illustrated in Figure 4; i. e., in position to prevent movement of latch plate 13 and latch member L from door latched to door unlatched position.

The bent end of actuating rod 66 opposite grasping portion 61 is received within a hole 68 in the inwardly extending shank of restraining member 55 which is split as shown in Figures 4 and 11 to provide a retaining finger 69 which prevents inadvertent separation of the parts.

Figures 3, 4 and 11 also show the manner of employment of key-controlled actuating means, operating independently of actuating rod 66, for moving restraining member 55 between latchlocked and latch-unlocked positions. Such keycontrolled actuating means include a link 1| pivoted on a pin 12 located in the inwardly extending shank of restraining member 55. At its lower end, link H is connected to a lever," by a pin and slot connection designated generally, 13a. The inner end of lever 13 is pivotally mounted on housing H and square shaft 14 forms a connection from cylinder lock 15 to lever 13 (see Figure 3). Cylinder lock 15, which is operated bya key (not shown), permits of limited movement of lever '13 between the two dotted line position-s l3 and 13" shown in Figure 4. In the upper of these positions, lever '13, acting at the upper end of the slot in link H, forces restraining member 55 out of engagement with latch plate l3; in the lower of these positions, lever 13, acting at the lower end of the slot in link 1|, forces latch-restraining member 55 into engage-'- ment with latch plate l3.

With the parts in the relationship shown in Figure 3, that is to say with latch plate l3 and latch member L in door-latched position and with restraining member 55 in latch-locked po-' sition, operation of the mechanism to permit opening of the door involves first moving restraining member 55 from the locked position shown in full lines in Figure 4 to the unlocked position shown in full lines in Figure 11. From the inside ofthe vehicle this may be done by pulling upward on grasping portion 51 of actuating rod 66. From the outside of the vehicle, the same result may be accomplished by turning the key in cylinder lock I5 in a direction such as to move lever 13 into the upper dotted line position 13' shown in Figure 4. Until the unlocking operation has been done, either from inside or from outside the vehicle, latch plate I3 and latch member L are effectively held against movement into unlatched position.

Assuming that the door is closed and latched and that restraining member 55 is in unlocked position and it is desired to open the door, the first step is for the operator to grasp handle 33 and at the same time press plunger 3| in until it reaches the position indicated in dotted lines in Figure 5 and in full lines in Figure 10. The result is to move control slide member 21 into a fully retracted position in which there is no opportunity for interference between either the blocking portion (the upper end of off-set 39a) or the secondary blocking portion (the step 40) of control slide member 21 and latch plate l3. By simultaneously exerting a pull on handle 33 to move door D to the right as seen in Figure 3, latch member L, due to its engagement with keeper pin P, is caused to rotate clockwise as seen in Figures 3, 6 and 10 until latch plate 13 and latch member L assume the door-unlatched positions shown in Figure 10, by which time arcuate flange 22 on latch stop portion 2| encompasses lower off-set portion 39b of control slide member 21, thereby preventing return movement of control slide member 21 from the retracted position shown in Figure 10 to the blocking position of Figure 3.

Comparable actuation and operation of door D from within the vehicle, restraining member 55 being in latch-unlocked position, involves the application of pressure to push button assembly 53, which results in movement of operating arm 45 from the position shown in solid lines in Figures 3 and 10 to the position shown in phantom lines in Figure 10, coupled with the exertion of pressure against door D until it has swung from closed to open position. At this time, pressure on push button assembly 53 may be released, permitting operating arm 45 to return from the phantom line position shown in Figure 10 to its normal erect position shown in full lines in each of Figures 3, 6 and 10. Control slide member 21 is not, however, thereby permitted to return to its initial position, being held in retracted position in consequence of the fact that lower off-set portion 39b is encompassed by arcuate flange 22 as indicated in Figure 10.

This state of affairs, which obtains so long as door D continues in open position, is characterized, among other things, by the fact that plunger 3| remains retracted within guide 32.

Assuming now that it is desired to close door D, the latter is pushed from the outside or pulled from the inside of the vehicle until latch member L engages pin P, when rotary movement of latch plate 13 is initiated. If the closing force is sumciently strong, latch plate I3 as seen in Figure 10 moves counterclockwise until arcuate flange 22 moves completely out of engagement with control slide member 27, thus permitting control slide member 21 to return to its normal blocking position of Figure 3. By this time, snapover spring 23 has ceased to urge the latch plate [3 in unlatching direction and urges it, together with latch member L, in latching direction. When abutting face I! on abutment portion It strikes flange 1a, rotary movement :of latch plate I 3 in'latching direction necessarily ceases.

Latch member L has of course now attained the position indicated in Figure 3; that is to say, it is in door-latched position. If it is desired to lock the door restraining member 55 may then be moved into latch-locked position .as shown in Figures 3 and i. This may be done by downward movement of grasping portion .or knob 61 on actuating rod 66or :by turning the key in cylinder lock 15 in a direction such as to cause lever T3 to move into the lower phantom line positionl3", indicated in Figured. .At this stage, the parts are again in door-latched an'd loched position.

Between the above described latched and unlatched positions of door D is an intermediate or secondarylatched position illustrated in Figure 6 in which arcuate ilange 22 on latch plate 13 abuts step 40 which constitutesa secondary blocking portion between off -set portion 39a and off-set portion 39b of control slide member 21. In this secondary blocking positionof control member 21, off-set portion 39a is encompassed by arcuate flange 22, as shown, for example, in Figure 7 and control slide member 21 is :slightly retracted, as indicated by the clearance appearing in Figure 6 between flange 3'50. and the .end of rectangular slot 31 in cover plate 8. If the force employed in pushing or pulling door D toward closed position is insufiicient to efiect-complete-closing of the door against the cQ-acting portion of body latch plate [3 and latch member L- will be held in secondary latched position by "the blocking action or step 40 against the and race of flange 22 as seen in Figure 6. Thus the door will be held in secondary latched position even though not fully closed and latched.

The application of further force in closing direction continues the counterclockwise movement of latch plate [3 and permits the parts to move from the intermediate or secondary latched position illustrated in Figure 6 to the latched position shown in Figures 3 and 4. The door may of course stop in the secondary latched position if improperly closed but will usually move through the secondary 'i-nto'the latched position. The latch releasing force applied to plunger 31 or push button assembly 53 when is desired to unlatch and open the door should be suflicient to move control slide member 21 past the slightly retracted position of Figure 6 into fully retracted position shown in Figure 10 in which the latch member L is completely released for unlatching movement;

A modified form oflateh mechanism is shown in Figures 14 to 18, from which, for the sake of simplicity, are omitted certain elements nor mally used therewith as the restraining or locking mechanism. The principle upon which the latch mechanism of Figures 14 to 18 operates is similar to that of the latch mechanism already described. A principal point of difierence resides in the fact that the modified mechanism of Figures 14 to 18 employsa difierent type of snapover spring mechanism and has no intermediate or secondary latchedposition between the latched and unlatched positions of the latch plate and latch member.

In the latch mechanism of Figures 14 to 18 a base plate ea is employed which has on one side thereof a long flange 81' that is turned inward at right angles to base plate 813. Justv below the middle of long. flange Si is a vertical slot 82 (see Figure that helps position the cover plate.

i0 On the opposite side of :base plate '80 :is -'a short flange 83 which, like flangeGLprojects inward at right angles thereto, although not so :far inward as flange 6i. Short tfiange 83 is characterized, at a point opposite slot 82 in long flange :81, by a cut-away portion 84 in the inner edge thereof which, as seen in end elevation in Figure 18, is generally channel-shaped. Above and below cutaway portion 8 3 areiguides'85a and 85?) which are integral with short flange '83 and are struck up therefrom when channel-shaped cut-away portion dd is formed therein.

Extending parallel to base plate 80 and making contact atits vertical edges with long flange 8| one one :side and-short flange 83 on the otherside of base plate 88 is .a cover plate 81., itself provided with a bottom flange 81 11 that i turned toward and abuts against base plate 89. Cover plate s? is provided on the side which abuts short flange 83 by a tongue'at and on the opposite side; that is to say, the side which cooperates with long flange 8- l, by a tongue 88. The latter slides into and projects through slot 8'? in long flange ii'l Formed integrally with tongue 86 on lthe'side of cover plate 81 which cooperates with short flange '83 are lips 89a :and 89b which are adapted to slide over and encompass guides 85a and 8511, respectively.

Control slide member "9|, which is generally similar to control slide member 21, extends through channel-shaped cut-away portion M in short fiange t3 into the housing formed by base plate iii] and "cover plate 36. Control slide member 9*! diners from control slide member 2! in that it has a single-offse't portion 92, extending laterally, which is .not itself divided into upper and lower off-set portions but instead is charactenized by a smooth contour of 'arcuate configuration. Control slide member 91 is provided at its inboard end with an in-turned flange 93 which carries thereon a projecting extension 94 that extends inwardly through "an o ening 95 cover plate 81. It is guided in its lateral movement by means of two in-turned guide flanges, 96a and 9619, which are :formed integrally with cover plate 3'! above and below opening "95. A leaf spring '9! i positioned between projecting extension 9'4 and long flange 81, its lower end 91a projecting through an opening inbottom flange Bio of cover plate 87.

Cooperating with projecting extension 9'4 is an operating arm 38 which is rigidly affixed, as at 98a, to a shaft 99 forming part of a manually operated remote control actuating mechanism mounted inside the vehicle "door.

Latch plate Hi1 is generally similar to latch plate it, having a rounded lower portion and an irregularly shaped upper portion. The latter includes an abutment portion I62 which makes contact wtih long flange 81 or short flange 83', as the case may be, depending on the position of latch plate 101. It also includes a latch stop portion H13 provided with an in-turned arcuate flange mic adapted to encompass off-set portion 92 on control slide member 9!. Between abutment portion 82 and stop portion [93 is a V-' notch Hi l. On the opposite side of abutment portion H32 is a rectangular notch I85 by means of which locking engagement may be made with a restraining member (not shown but which may be similar to that illustrated in the embodiment of Figures 1 to 13). Latch plate Illl is normally in one or the other of the two terminal positions shown in Figures 14 and 15 and in moving from one to the other passes through but does not stop in other intervening positions.

Near the top of abutment portion I02 of latch plate IN is a stud I06 which projects through and is pivoted for angular movement relative to abutment portion I02. At the inner end thereof, stud I06 carries a ring-shaped retainer I01 which is integral with stud I06. An L-shaped bracket I08 pvoted at I080 on base plate 80 coact with ring-shaped retainer I01. Between them is disposed a compression Spring I09 which is held in position by a spring guide pin Il secured to bracket I08. As the assembly shown in Figure 16 moves between the latched position of Figure 14 and the unlatched position of Figure 15, pressure on compression spring I09 first increases from a minimum to a maximum, corresponding to a straight-line position, and then decreases to a minimum. On the two sides of its mid-position, compression spring I09 urges latch plate IOI clockwise or counterclockwise, depending on the position of the spring axis. The operation of the device of Figures 14 to 18 is substantially like that of Figures 1 to 13 except that the secondary latched position is omitted.

A further modification is shown in Figures 19 to 22. In the embodiment of the invention therein illustrated, base plate I20 has a long flange I2l extending inward throughout the full length thereof and, on the opposite side, a short flange I22 likewise extending inwardly. Cooperating with these elements is a cover plate I23, generally similar to cover plate 8, having upper and lower end walls I24a and I24b parts of which project through base plate I20 and are bent over into contact therewith as shown, for example, near the bottom of Figure 21. Thus base plate I20 and cover plate I23 together make up a housing very similar to housing H already described.

Cover plate I23 has near the top thereof a round opening I25 and, toward the bottom thereof, an arcuate slot I26. The upper lefthand corner of cover plate I23 is cut-away as seen at I2'I in Figures 19 and 20. The space so provided is adapted to accommodate a looking or restraining member (not shown). Adjoining the cut-away I2! is an open slot I28 defined in part by upper and lower in-turned guide flanges I29a and l29b, which guide flanges are integral with cover plate I23. Although differently positioned in that it is located at a somewhat higher level, slot I28 is analogous to and serves the same purposes as slot 3! and opening 95 in the two embodiments of the invention previously described. Below the level of slot I28, cut-away portion I21 terminates at a level such as to enable it to receive the lowermost parts of a, looking or resltzaining member of the type shown in Figures A control slide member I3I is employed which is similar to control slide member 9| in the embodiment of the invention shown in Figures 14 to 18, but specifically different in respects hereinafter explained. Like control slide member 9|, it is characterized by a lateral oil-set I32 which is not broken into upper and lower off-set portions but takes the form of a smooth curved surface of arcuate conformation. At its opposite or inboard end, control slide member I3I has an inturned flange I33 which extends inward toward, but does not project through, cover plate I23. A leaf spring I34 similar to springs 42 and 91 in the embodiments of the invention previously described is mounted in contact with long flange I2I. Its upper and lower ends respectively en- 12 gage end flange I33 on control slide member I3I and the bottom flange which forms lower end wall I341) of cover plate I23.

Projecting from the body of control slide member iEzi near the inboard end thereof is an upwardly extending portion I35, formed as shown in Figure 19. It has on one side thereof an inturned flange I38 which projects into slot I28 between upper and lower guide flanges I25; and I291). Cooperating therewith is 9. depending operating arm I37 fixed to remote control shaft I38 as at I3'Ia. Operating arm I31 depends from shaft I38 in juxtaposition to inturned flange I36 on upwardly extending portion I35 of control slide member I3I. Positioning operating arm I31 and shaft I38 in the manner shown in Figures 19 and 20 permits the remote control system used in manually actuating control slide member I3I from within the vehicle to be located at approximately the level of the handle on the exterior of the vehicle. This arrangement may be desirable in some installations.

Latch plate I40 is similar to latch plate IOI in the embodiment of the invention illustrated in Figures 14 to 18. It is characterized by an abutment portion MI, by a latch plate stop portion Hi2 having thereon an arcuate flange I42a, and by a notch I43 adapted to receive the latch-plate engaging element of a locking or restraining member (not shown), such rectangular notch I43 coinciding generally with the lowermost part of cut-away portion I21 when latch plate I40 is in latched position shown in Figure 19.

Opposite abutment portion I4I, latch plate I40 carries a downwardly projecting extension I44 equipped with an in-turned flange I45. One end of a tension spring I46 passes through a suitable opening in flange I45, being held against displacement by the bent end portion I46a forming part thereof. The other end of tension spring I46 surrounds a fixed stud I41 mounted on base plate I20 and projecting through opening I25 in cover plate I23. As latch plate I40 moves between the latched and unlatched positions indicated respectively in Figures 19 and 20, the lower end of tension spring I46 moves from one end to the other of arcuate slot I25. Tension on the spring increases from a minimum at one end of the travel of flange I45 to a maximum when the center line of the spring crosses the center of rotation of latch plate I40 and decreases again as flange I45 moves to the opposite end of its travel in slot I26. When in the position of Figure 19 the spring I46 tends to hold latch plate I 40 and latch member in latched position but when in the position of Figure 20 it tends to hold the parts in their unlatched positions. Thus the operation of this embodiment is substantially the same as that of Figures 14 to 18.

In the various embodiments of the invention heretofore described, two steps are necessary to go from door-latched to door-unlatched position. One of these steps involves the application to the control slide member of a manually imposed force, exerted either from an inside remote control station or from outside as on push button 3| in the embodiment of the invention shown in Figures 3 to 13. The second step is the application of an opening force to the door itself which will operate to cause latch member L to slide over keeper in P, this operation giving rise to rotary movement of the latch plate.

The embodiment of the invention shown in Figures 23 to 27 has for an object to avoid the necessity for exerting a direct opening force on the: door, at" least, insofar: as concerns operation of the door from the interior of the vehicle. Pursuant to themethod of' operation inherent. to. the apparatus in Figures 23' to. 27, only a single force,.such as rotation of :a handle orsother'device located at the remote control station on the inside of; the vehicle door, is;necessary toreftect opening ofthe' door. As:regardsa person-on the outside; of the vehicle, the; mechanismzillustrateid in Figures 23 to 27, doesnot change the prem'ous'l describedstateof: aifairs; thatisito say, .theinitial application ofamanual force totoperate the controlslide member. must stillbe followed by. the application of a force to'move the door in openingdirection andthusrotate the latch plate and latch member: into unlatched position;

The mechanism of Figures 23 to 27 includesa basexplate' lflshaving. on one side thereof a long flange ISI extending inward" from top to bottom thereof and, on the opposite side thereof, a short fiange I521 Cooperating with base plate- I5'Ilto form: a housing-is a cover plate I53 whichdoes not abut eitherlong'fiange I5I or short-flange I52- but is held in-pla'ce by end walls I540 and I541), portions of which are turned toward each other on the'opposite side of baseplate I 50'. As seen in Figure 23, cover plate I53 is characterized by an=open slot I55onthe side'thereofnexttolong flange 151.

A control slide member I55; similar to the control slide member 21 of Figures 1 to 13, extends into-the housing so formed and is guided on one side thereof by upper and lower housing lips lila'and I511) and, on the opposite side'thereof, by'the disposition-in slot I55 of an in turnedend flange I58" on the control slide member itself; Like the control slidem'ember" illustrated in the embodiment of theinvention shown in Figures 19 to 22- and unlike the control slide member shown in previously described embodiments of the invention; control slide member I56 has no inwardly projecting extension or iii-turned end flange- I58: instead; leaf spring I59 presses directly against the posterior or far face of end flange I582 The opposite end, I590, projects through lower wall I541) ofcover plate I53; being suitably bent to preclude possible displacement. Control slide member I'5Iiis characterized by a lateral off -set' which is itself divided into upper and'loweroffisetsl50a and I801),- muchas in the embodiment of the invention shown in Figures 1 to 13;

Latch plate IE1 is similar to the latch plate incorporated in the latch mechanism shown in. Figures 1 to 13, being characterized by a latch stop-portion I62 provided with an i'n-turned arcuate flange I62a. Elsewhere; latch plate 161 is characterized by an abutment portion I83 which comes to rest against long flange I51 or short flange I52, dependingon whether the-latch plate I'GI" is inthe latched position of Figure 23 or theunlatched position of Figurez'li Abutment portion I63 coacts with a snap-over spring I8 1; thefixed end of which, I65, projects into-a hole-in cover plate I53-and the free end-ofwhich, I66, projects in the opposite direction through a hole in abutment portion I63". To avoid inter ferenoe between the parts, base plate I50 is provided with an arcuate slot I61 into which projects free'end I66 of snap-over spring I54 Latch plate I61 is carried upon a shaft I68, 'our-naled in baseplate I50, to the opposite end of which is fixed latch member L with legs-L"and1 L," as shown in Figures 23', z t and 2'1;

Mounted on long flange I51 is a T-shape'd1 restraining: member I 69" like that shownain Figures 1 to 13 and similarly operable by a manuallycontrolled actuatingsrodor a key-controlled lever having a pin-andZ-slot connection with a link depending from the shank of latcherestraining member I69. These parts are not described in detailas they are substantially'the same asi-those previously described.

A remote control system including a suitable insiderotary handle (notshown) isprovided; this handlebeing connected to operate a remote-control shaft-1H journaled-at I1Ia'at base plate I50; On, shaft I11 near the point where the shaft is journaled in base plate I 50- is an operating arm I12 which has formed integrally therewith. an annular hub portion I13 bearing against. andrfite ting into a suitably formed opening in cover plate I53. Operatingarm I12 has a finger. I14 projecting'laterally therefrom which is best seen in Figures '23 and 26. As shownin- Figure 2-1, operating arm I12 is bent inwardout of a vertical plane; this for the, purpose of enabling it to make contact through finger I14 with a rotary actuating member I 15wsupported on cover plate 153. as by a pivot pin 116-. Rotary actuating member'I15 has a depending portion I11 through which contact ismade with finger! on operat-.- ing arm: I12.

Proceeding'clockwise around the periphery of rotary actuating member I15 from depending portion 12111; next to'be encounteredis an-angular portion I18 engaging the anterior or near face'of in-turnecl flange I5fi on control. slide member I56; Angular portion I18 is characterized by a relatively sharp but neverthelessslightly rounded corner I19, on opposed. sides-of which are two flat surfaces" IBIa and. I8Ib. In door-latched position; shown in Figure 23, surface, I8Ia abuts against. flange. I58; in. door-unlatched. position, shown in Figure-2'1, surface I811) abuts against flange I58.- In the intermediate positions, such as that illustrated. in Figure'26, rotary actuating member I: assumes: a position in. which contact with flange I58 is by corner I19.

Continuing. clockwise around rotary actuating member I15,.surface IBIa, extends in a generally upward direction to form part: of latch-plate moving portion I82. The latter is characterized, among other things, by a fiat side I83 adapted to make contact with the adjacent end ofarcuateflange I620, on latch stop portion IIiZ-of latch plate1I6 I. Inproceeding fromthe position shown in Figure 23 through that shown in Figure 26 to thatishown in Figure. 27,.latch-plate moving portion I82 firstmakes contact with arcuate flange I62a'on latch stop portion I62; after which con.- tinued exertion of force on rotary actuating. member. I15v throughoperating arm I12 and shaft I1AI-' resultszin clockwise movement of latch plate I61, which: ultimately comes to rest in the un latched position shown in Figure 27.

At this stage, rotary actuating member I15 it self comes to rest asa result of the fact that flat surface I8I:b abuts the anterior face of flange I5il'on control. slide member. 156. The latter, by virtue of movement of corner I19 in a clockwise direction, has already'been fully retracted sothat off-=setportions Ifiilc and [5% are out of the path of latch: stop portion I62 of latch plate I5I (see Figure 27'). Thus a single continuously acting force exerted at the remote control station on a handleor other device associated with shaft Ill first eiieotsretraction of control slide member I56 and then causes rotation of latch plate I61 into unlatched position, this as a result of the coaction 1 5 of operating arm I12 and rotary actuating member I'I5.

With the parts in the position shown in Figure 27, a closing force applied to the door will result in rotation of latch member L and, with it, shaft I68 and latch plate I6I. The direction of rotation will be counterclockwise as seen in Figure 27. As such movement proceeds, arcuate fiange I62a on latch stop portion I62 of latch plate I6I will likewise move counterclockwise, clearing first lower off-set portion I601) on control slide member I56 and, provided the force is sufficiently great, also upper off-set portion I60a. If, however, the force is insufficient fully to close the door and to cause stop portion I62 to clear both upper and lower off-set portions I'60a and IGUb, latch plate I6I comes to rest with arcuate flange I 62a of latch stop portion I62 in contact with the step formed between upper and lower off-set portions IBM and I661). The parts are then in their secondary latched positions. Resumption of the closing force, if so interrupted, results in further movement of latch plate I6I in a counterclockwise direction, clearing upper off-set portion I6 Ia and permitting control slide member I56 and rotary actuating member I65 to return to the latched position illustrated in Figure 23.

Although several different embodiments of the door control mechanisms of the invention have been illustrated and described in detail, it will be apparent to those skilled in the art that variations and modifications, whether by way of simplification or elaboration, may be made as desired in the arrangement, form, proportions and manner of co-action of the various elements. It will further be apparent that the door control mechanisms of the invention may be adapted to make use of mechanisms of other types than those as specifically illustrated and described in the invention. The invention is therefore not to be understood as limited to the particular devices shown and described but as contemplating all embodiments thereof coming within the scope of the appended claims.

It is intended that the patent shall cover, by suitable expression in the appended claims, whatever features of patentable novelty reside in the invention.

I claim:

A door latch mechanism comprising a frame structure, a latch member supported by said frame structure for rotary movement relative thereto between a door latched position and a door unlatched position, a snap-over spring secured at one end to said frame structure and having its other end movable with and effective upon said latch member, said other end of said spring being disposed on one side of the common center line between said one end of said spring and the center of rotation of said latch member when said latch member is in said door latched position and on the other side of said common center line when said latch member is in said door unlatched position. said spring being loaded to a maximum degree when said other end of said spring is on said common center line and to a lesser degree when said other end is on either side of said common center line whereby said latch member is urged toward said door latched position during a portion of its travel between said positions and toward said door unlatched position during the remainder of its said travel, a latch stop member supported for limited rotary movement with said latch member and having an inwardly extending arcuate flange portion, a control slide member,

means on said frame structure for supporting and guiding said control slide member for straight line sliding movement transversely of the axis of rotation of said latch member between a latch stop member blocking position and a latch stop member released position, control slide spring means effective at all times to urge said control slide member toward its said blocking position, said control slide member having an outwardly extending arcuate portion one end of which is disposed in the path of movement of one end of said inwardly extending arcuate flange portion on said latch stop member when said latch member is in door latched position and said control slide is in said blocking position whereby movement of said latch member into door unlatched position is blocked. said inwardly extending arcuate flange portion of said latch stop member being adapted, when said control slide has been moved into said released position and said latch member has been moved into door unlatched position, to be engaged by said outwardly extending arcuate portion of said control slide member whereby said control slide is held in said released position against the action of said control slide spring means, said arcuate portions of said latch stop member and said control slide member being formed on radii drawn from the center of rotation of said latch member, and manually operable means for moving said control slide from said blocking to said released position.

2. A door latch mechanism comprising a frame structure, a latch member supported by said frame structure for limited rotary movement relative thereto between a door latched position and a door unlatched position, a snap-over spring secured at one end to said frame structure and having its other end movable with and eifective upon said latch member, said other end of said spring being disposed on one side of the common center line between said one end of said spring and the center of rotation of said latch member when said latch member is in said door latched position and on the other side of said common center line when said latch member is in said door unlatched position, said spring being loaded to a maximum degree when said other end of said spring is on said common center line and to a lesser degree when said other end is on either side of said common center line whereby said latch member is urged toward said door latched position during a portion of its travel between said positions and toward said door unlatched position during the remainder of its said travel, a latch stop member supported for limited rotary movement with said latch member and having an inwardly extending arcuate flange portion, a control slide member, means on said frame structure for supporting and guiding said control slide member for straight line sliding movement transversely of the axis of rotation of said latch member between a latch stop member blocking position and a latch stop member released position, control slide spring means effective at all times to urge said control slide member toward its said blocking position, said control slide member having an outwardly extending arcuate portion one end of which is disposed in the path of movement of one end of said inwardly extending arcuate flange portion on said latch stop member when said latch member is in door latched position and said control slide is in said blocking position whereby movement of said latch member into door unlatched position is blocked, said inwardly extending arcuate flange portion of said latch stop member accuses being adapted, when said control slide has been moved into said released position and said latch member has been moved into door unlatched position, to be engaged by said outwardly extending arcuate portion of said control slide member whereby said control slide is held in said released position against the action of said control slide spring meanasaid arcuate portions of said latch stop member and said control slide member being formed on radii drawn from the center of rotation of said latch member, manually operable means for moving said control slide from said blocking to said released position, a restraining member supported on said frame structure for movement between a latch locked position and a latch unlocked position, a restraining member engaging element supported for movement with said latch member, said restraining member when in said locked position being in the path of said ele ment whereby movement of said latch member from door latched position into doorunlatched position is prevented, and manually operable means for moving said restraining member between said latch locked and unlocked positions.

3. A door latch mechanism comprising a frame structure, a latch member supported by said frame structure for limited rotary movement relative thereto between a door latched position and a door unlatched position, a latch plate supported for movement with said latch member, a snapover spring anchored at one end to said frame structure and having its other end operatively connected to said latch plate, said other end or said spring being disposed on one side of the common center line between said one end of said spring and the center of rotation of said latch member when said lat-ch member is in said door latched position and on the other side of said common center line when said latch member is in said door unlatched position, said spring being loaded to a maximum degree when said other end of said spring is on said common center line and to a lesser degree when said other end is on either side of said common center line whereby said latch member is urged toward said door latched position during a portion of its travel between said positions and toward said door unlatched position during the remainder of its said travel, a latch stop member on said latch plate having an inwardly extending arcuate flange portion, a control slide member means on said frame structure for supporting and guiding said control slide member for straight line sliding movement transversely of the axis of rotation of said latch plate between a latch stop member blocking position and a latch stop member released position, control slide spring means effective at all times to urge said control slide member toward its said blocking position, said control slide member having an outwardly extending arcuate portion one end of which is disposed in the path of movement of one end of said inwardly extending arcuate flange portion on said latch stop member when said latch member is in door latched position and said control slide is in said blocking position whereby movement of said latchm'ember into door unlatched position is blocked, said inwardly extending arcuate flange portion of said latch stop member being adapted, when said control slide has been moved into said released position and said latch member has been moved into door unlatched position, to be engaged by said outwardly extending arcuate portion of said control slide member whereby said control slide is held in said released position against the action of said control slide spring means, said arcuate portions of said latch stop member and said control slide member being formed on radii drawn from theoenter of rotation of said latch member, and manually operable means for moving said control slide from said blocking to said released position.

4. A door latch mechanism comprising a frame structure, a latch member supported by said frame structure for limited rotary movement relative thereto between a door latched position and a door unlatched position, a latch plate supported for movement with said latch member, a snap-over spring anchored at one end to said frame structure and having its other end operatively connected to said latch plate, said other end of said spring being disposed on one side of the common center line between said one end of said spring and the center of rotation of said latch member when said latch member is in said door latched position and on the other side of said common center line when said latch memher is in said door unlatched position, said spring being loaded to a maximum degree when said other end of said spring is on said common center line and to a lesser degree when said other end is on either side of said common center line whereby said latch member is urged toward said door latched position during a portion of its travel between said positions and toward said door unlatched position during the remainder of its said travel, a latch stop member on said latch plate having an inwardly extending arcuate flange portion, a control slide member, means on said frame structure for supporting and guiding said control slide member for straight line sliding movement transversely of the axis of rotation of said latch plate between a latch stop member blockingposition and a latch stop mem ber released position, control slide spring means effective at all times to urge said control slide member toward its said blocking position, said control slide member having an outwardly extending arcuate portion one end of which is disposed in the path of movement of one end of said inwardly extending arcuate flange portion on said latch stop member when said latch memher is in door latched position and said control slide is in said blocking position whereby movement of said latch member into door unlatched position is blocked, said inwardly extending arcuate flange portion of said latch stop member being adapted, when said control slide has been moved into said released position and said latch member has been moved into door unlatched position, to be en aged by said outwardly extending arcuate portion of said control slide member whereby, said control slide is held in said released position against the action of said control slide spring means, said arcuate portions of said latch stop member and said control slide member being formed on radii drawn from the center of rotation of said latch member, manually operable means for moving said control slide'from said blocking to said released position, a restraining member supported on said frame structure for movement between a latch locked position and a latch unlocked position, a restraining member engaging element supported for movement with said latch member, said restraining member when in said locked position being in the path of said element whereby movement of said latch member from door latched position into door unlatched position is prevented, and manually operablemeans for moving said restraining member between said latch locked and unlocked positions.

5. A door latch mechanism comprising a frame structure including a base plate, a shaft supported. by said frame structure, a latch member rotatable about the axis of said shaft and disposed on one side of said base plate, a latch plate rotatable with said latch member and disposed on the opposite side of said base plate, said latch plate having a latch stop portion, a locking abutment portion, and a spring receiving slot extending at an oblique angle to radii drawn from the center of rotation of said latch plate through the ends of said slot, a snap-over spring having a coil portion and spaced end portions, one of said end portions being anchored on said frame structure and the other end portion extending into said slot, said latch member being movable between a door latched position and a door unlatched position, said slot being positioned on one side of the common center line of said shaft and said one end of said spring when said latch mem ber is in door latched position and on the other side of said common center line when said latch member is in door unlatched position, said spring being loaded to a maximum degree when said other end of said spring is on said common center line and to a lesser degree when said other end is on either side of said center line, and control means for select vely blocking said stop portion of said latch plate against movement from door latched to door unlatched position and releasing said stop portion to permit movement from door latched to door unlatched position.

6. A door latch mechanism comprising a frame structure including a base plate, a shaft supported by said frame structure, a latch member rotatable about the axis of said shaft and disposed on one side of said base plate, a latch plate rotatable with said latch member and disposed on the opposite side of said base plate, said latch plate having a latch stop portion, a looking abutment portion, and a spring receiving slot extending at an oblique angle to radii drawn from the center of rotation of said latch plate through the ends of said slot, a snap-over spring having a coil portion and spaced end portions, one of said end portions being anchored on said frame structure and the other end portion extending into said slot, said latch member being movable between a door latched position and a door unlatched position, said slot being positioned on one side of the common center line of said shaft and said one end of said spring when said latch member is in door latched position and on the other side of said common center line when said latch member is in door unlatched position, said spring being loaded to a maximum degree when said other end of said spring is on said common center line and to a lesser degree when said other end is on either side of said center line, control means for selectively blocking said stop portion of said latch plate against movement from door latched to door unlatched position and releasing said stop portion to permit movement from door latched to door unlatched position, and restraining means supported on said frame structure for movement into and out of the path of said locking abutment portion.

'7. A door latch mechanism comprising a frame structure, a latch member supported by said frame structure for movement relative thereto between a door latched position and a door unlatched position, said latch member also having a secondary latched position between said latched and unlatched positions, a snap-over spring secured at one end to said frame structure and having its other end movable with and effective upon said latch member, said other end of said spring being disposed on one side of the common center line between said one end of said spring and the center of rotation of said latch member when said latch member is in said door latched position and on the other side of said common center line when said latch member is in said door unlatched position, said spring being loaded to a maximum degree when said other end of said spring is on said common center line and to a lesser degree when said other end is on either side of said common center line whereby said latch member is urged toward said door latched position during a portion of its travel between said positions and toward said door unlatched position during the remainder of its said travel, a latch stop member supported for movement with said latch member, a control slide member supported by said frame structure for straight line sliding movement between a latch stop member blocking position and a latch stop member released position, said control slide member having a secondary blockingposition between said blocking and released positions, means for urging said control slide member toward its said blocking position, said control slide member having an arcuate blocking portion one end of which is disposed, when said stop member is in door latched position and said control member is in blocking position, in the path of movement of said latch stop member whereby substantial movement of said latch member toward door unlatched position is blocked, said control slide member also having a secondary arcuate blocking portion spaced from said first named arcuate blocking portion and adapted to block said stop member in secondary latched position, and means operable from a side of a door with which the latch mechanism is associated for moving said control slide member from said blocking to said released position, said latch stop member having an arcuate portion adapted, when said control slide member has been moved toward said released position and said latch member has been moved into either secondary latched or unlatched position, to engage one of said arcuate portions of said control slide member and hold same against movement into said blocking position until said latch member has been returned to door latched position.

8. A door latch mechanism comprising a frame structure, a latch member supported by said frame structure for movement relative thereto between a door latched position and a door unlatched position, said latch member also having a secondary latched position between said latched and unlatched positions, a snap-over spring secured at one end to said frame structure and having its other end movable with and effective upon said latch member, said other end of said spring being disposed on one side of the common center line between said one end of said spring and the center of rotation of said latch member when said lat-ch member is in said door latched position and on the other side of said common center line when said latch member is in said door unlatched position, said spring being loaded to a maximum degree when said other end of said spring is on said common center line and to a lesser degree when said other end is on either side of said common center line whereby said latch member is urged toward said door latched posie aca emic 2i tion; duringv a. portion of itstraveli between said positions and toward: said; door" unlatched: position during thev remainder of it's said travel? a latch stop. member" supported for movementwith said latch member; a control: slide-z member supported by said: frame structure-tor straightv line sliding movement. between a latch stop member blocking position. and. a: latch. stop. member released position, said control slide member having asecondary blocking position between; said blocking and released positions, means tor urging said control slide member" toward its. said blocking position, said control! slide member" havig" an arcuate blocking: portion: one. end? of" which is disposed, when said stop: member is in door latched position: and sai'd control member is-in blocking position, the; patli of movement? of saidlatch stop member: whereby: substantial movementot said latch: member toward door'un latched position is blocked saidl con-trol slide member also having a secondary: arcuate" blocking portion spaced from said ii rstnamed arouate blocking portion andadapted to block said stop member in secondary l atched position, means: op.- erabl'efrom a side of a door with which: the latch mechanism is: associated for movingsaid control slide member from said" blocking to said released position", said latchstop member having an as ouate portion adapted, when said controli slide member has been moved toward said released position said latch member has: been moved into either secondary" latched or unlatched: position, to engage one of said arcuate portions. or saidslide member and hold same against movement into said blocking position until said latch member has been returned to door latched position, alatch restraining member supported on said framev structure for movement between a latch locked position and a latch unlocked position, a restraining member: engaging element supported for movement with said latch member, said restraining member when insaid locked position being in the path of said, element whereby movement of said latch, member from. door latched: position into door. unlatched position is prevented and manually operable means. for moving said restraining member between said latch locked and unlocked positions.

9. A door latch mechanism comprising a frame structure, a latch member supported by said frame structure for movement relative thereto between a door latched position and a door unlatched position, said latch member also having a secondary latched position between said latched and unlatched positions, a snap-over spring secured at one end to said frame structure and having its other end movable with and effective upon said latch member, said other end of said spring being disposed on one side of the common center line between said one end of said spring and the center of rotation of said latch member when said latch member is in said door latched position and on the other side of said common center line when said latch member is in said door unlatched position, said spring being loaded to a maximum degree when said other end of said spring is on said common center line and to a lesser degree when said other end is on either side of said common center line whereby said latch member is urged toward said door latched position during a portion of its travel between said positions and toward said door unlatched position during the remainder of its said travel, a latch stop member supported for movement with said latch member between a door 22% latched: position. and a: doorunlatched: position; saidz stop. member also;- having a secondary positionzbetweem its said. latched and; unlatched; positions; av control slide. member supported said. frame; structure for: straight: line sliding movement: betweem a. latch; stop member blocking position: and a latch. stop" member re leasedposition-g, said: controh slide; member having: as secondary blocking position between: said blocking and. released positions; said? latche stop member and; saidzcontroi slide member having coacting; portions: engageable to: restrain saidlatch member; against movement into unlatched position. said: latched: position; and from. said secondarwlatehed,position,.meansfor urging: said control slide member-toward its: said'i blockingpositi'om. and means. operable: from. a. side. of a door with which therlatchmechanism is associated for moving-I saidz control slide member from: said blockingrto saidz releasedi position, said latch. stop member: having. an arcnate portion adapted, when said control membenhas; been moved toward; said released: position. and. said latch member has been moved into either secondary latched or unlatched position, to! engage correspondingly arouateportions: on saidi control slide, member and hold same against. movement. intosaid blocking positiomuntil: said latch member has beenreturned. to: door: latched posit-1011;.

1-11.: A: door latch mechanism, comprising a frame: structure; a. latch member supported by said frame: structure for movement relative thereto between. a door latched. position; and:v a. door unlatched position, said latch member alsm having a secondary latchedz position between said latched and unlatched positions, a. snap-over spring secured at; one. end. to: said frame structure having its; other end. movable with", and of.- tective upon: said: latcha member, said; other end of. said spring: being disposed. on. one side of. the common center: line-between said one; end of said spring and. the: center:- of rotation of said latch member. when; said latch member: is in: said; door latched! position and on; the other side, of said common center" line.- when. said latch. member is in: said door unlatched: position, said spring: being lioadedto amaximum; degree when said othen end of said; spring; is: on said common, center line and. to a lesser: degree: when said' other end; isv on either side of said common center line whereby said latch member is urged toward said door latched position during a portion of its travel between said positions and toward said door unlatched position during the remainder of its said travel, a latch stop member supported for movement with said latch member between a door latched position and a door unlatched position, said stop member also having a secondary latched position between its said latched and unlatched positions, a control slide member supported by said frame structure for straight line sliding movement between a latch stop member blocking position and a lat-ch stop member released position, said control slide member having a secondary blocking position between said blocking and released positions, said latch stop member and said control slide member having coacting portions engageable to restrain said latch member against movement into door unlatched position from said door latched position and from said secondary latched position, means for urging said control slide member toward its said blocking position, means operable from a side of a door with which the latch mechanism is associated for moving said control slide member from 

